From The Hutchinson Unabridged Encyclopedia with Atlas and Weather Guide

Reduction, limitation, or abolition of a country's weapons of war. Most disarmament talks since World War II have been concerned with nuclear-arms verification and reduction, but biological and chemical weapons of mass destruction, and conventional weapons have also come under discussion at the United Nations and in other forums. Attempts to limit the arms race (initially between the USA and the USSR and since 1992 between the USA and Russia) have included the Strategic Arms Limitation Talks (SALT) of the 1970s, the Strategic Arms Reduction Talks (START) of the 1980s–90s, the Strategic Offensive Reductions Treaty (SORT) of 2002, and the New START of 2010. These have led to a substantial reduction in the number of nuclear warheads held by the USA and Russia, the world's main nuclear powers.

In 1987, the USA had a stockpile of more than 31,000 nuclear warheads. By 2012 this had fallen to 2,200, with further reductions required under New START, which limits the USA and Russia to 1,500 warheads each by 2018. However, since the 1980s the number of nuclear weapon states in the world has increased, with India and Pakistan (both from 1998) and North Korea (from 2006) joining the original five (China, France, Russia, the UK, and the USA), while Israel was also believed to have nuclear capability and Iran was close to achieving it.

In the UK the Campaign for Nuclear Disarmament lobbies on this issue, while Greenpeace lobbies worldwide.

Before 1914 The enormous cost in lives and materials of World War I provided a considerable stimulus to efforts to reduce the arms race which had played a crucial role before 1914. International principles were laid down in the covenant of the League of Nations to that end, attempts were made by the League to secure a limitation on armaments, and limited disarmament treaties were made between some states (for example by Britain, the USA, and Japan on naval forces in 1930). The rise of the fascist dictatorships in Europe and the aggressive role of Japan in Asia effectively destroyed further attempts at general disarmament and the international situation steadily deteriorated, culminating in the outbreak of war in 1939.

After 1945 At the conclusion of World War II the world was confronted with the problem of controlling nuclear weapons and the related question of disarmament again came to the fore. The situation was made more serious by the increasingly sophisticated means of delivery, especially by nuclear submarines, and by other technological advances, such as satellites. The main problem was the lack of mutual trust between the Soviet bloc and the Western allies and, after the failure to limit armaments in the early post-war period through the establishment at the United Nations of a Conventional Arms Commission and an Atomic Energy Commission, attempts were made to impose unilateral disarmament on the states defeated in 1945.

The Cold War As the Cold War developed, attempts to impose unilateral disarmament were abandoned and the Soviet Union and the Western allies assisted in the rearming of the former enemy countries. In 1952 the two UN Commissions were merged into a new Disarmament Commission, but deadlock continued throughout most of the 1950s, with particular difficulty arising over the creation of reliable and mutually acceptable systems of inspection to enforce any agreements that might be reached. In 1958, however, it was agreed that it was possible to detect and identify certain types of nuclear explosions and this made possible the limited nuclear Test Ban Treaty signed by the USA, the USSR, and the UK in 1963. On 23 September 1996 the USA and other countries signed a Comprehensive Test Ban Treaty (CTBT), which bans all nuclear explosions for military and civil purposes. Although the CTBT has been ratified by more than 150 countries (as of 2012), it has not entered force because it has not been signed by three nuclear powers – India, North Korea, and Pakistan – and has been signed but not ratified by China, Iran, Israel, and the USA.

In 1959 the first of a series of treaties declaring nuclear-free zones of the world was signed. This first treaty banned nuclear weapons from Antarctica and was signed by 12 nations, including the USA, the USSR, the UK, and France. This was followed in 1967 by a treaty signed by 21 Latin American states banning nuclear weapons from Latin America, and a treaty signed by the USA, the USSR, and the UK banning nuclear weapons from outer space. Also in 1967 a nuclear non-proliferation treaty was signed by 59 states, including the three principal nuclear powers. By 2012 it had been signed by 189 countries, but not by four states which had nuclear weapons, or capability: India, Israel, Pakistan, and North Korea.

Further progress was made in the 1970s with an agreement in 1972 between the USA and the USSR to limit their antiballistic missile systems and in 1974 a limit on underground nuclear tests was agreed. A further agreement on underground tests allowing for the inspection of sites was signed by the USA and the USSR in 1976. These agreements between the USA and the USSR arose out of the continuing Strategic Arms Limitation Talks (SALT), which began in the early 1970s.

Conventional armaments The agreements on nuclear weapons were facilitated by the fear of nuclear war, a desire to limit military expenditure, and by technological developments, but the control of conventional armaments has proved more difficult, although some progress has been made.

Many years of discussion resulted in the holding of a three-stage Conference on Security and Cooperation in Europe between 1973 and 1975. The final stage in September 1975, in which 35 countries (the USA, the USSR, Canada, and all European countries except Albania) took part, reached agreement on a wide range of matters, including agreements to respect each other's sovereignty and frontiers, to refrain from intervention in each other's internal affairs, and to respect human rights and the right of self-determination. Apart from a general agreement to refrain from the threat or use of force as a means of settling disputes, and to give prior notice of and exchange observers at manoeuvres, no specific agreement on disarmament was reached.

Following a recommendation of the UN General Assembly, the Conference on Disarmament (CD) was set up in 1978. Based in Geneva, Switzerland, it has become the world's principal multilateral disarmament negotiating forum. Its objective is to promote the attainment of general and complete disarmament under effective international control. It held its first meeting in 1979, building on the 1963 Test Ban Treaty, the 1970 Non-Proliferation Treaty, the 1972 Seabed Arms Control Treaty, and the 1972 Biological and Toxic Weapons Convention. In 1992 it drafted the Chemical Weapons Convention, banning the production, stockpiling, and use of chemical weapons, which most countries in the world have signed. In 2001 the Conference called for urgent action to control and phase out short-range tactical nuclear weapons (TNWs). It estimated that Russia had deployed 4,000, with 12,000 in reserve, while the USA had about 150 stationed in Europe with a further 820 in the USA.

Twentieth-century advances in military technology made war exponentially deadlier and increased the urgency with which the international community has sought to maintain peace and limit the spread of nuclear and chemical weapons. Over the last 50 years, many countries—including those that possess…